Saturated Fats

Saturated fats are stable fats because there are no double bonds between the carbon and hydrogen atoms.  These fats resist rancidity and are solid or semi-solid at room temperature.  These fats are great to cook with because they can stand the stress of high heat without going rancid.  Examples of saturated fats are butter, beef tallow, coconut oil and palm oil.

Monounsaturated Fats

Monounsaturated fats contain one double bond between the carbon atoms.  They are relatively stable- more stable than polyunsaturated fats, but less stable than saturated fats.  They are liquid at room temperature and solid if put in the refrigerator.  They can be used to cook with at low to moderate heats.  Olive oil, canola oil, peanut oil and high oleic safflower oil are examples of monounsaturated fats.

Polyunsaturated Fats

Polyunsaturated fats are unstable and highly reactive because they have multiple double bonds between their carbon atoms.  They are liquid at room temperature and in the refrigerator.  Due to their unstable nature, they should never be used to cook with.  They easily go rancid when exposed to heat and light.  Most vegetable oils are classified as polyunsaturated oils; examples are corn, cottonseed, safflower, soybean and sunflower oil.

Damaged Fats

A damaged fat is any fat that is rancid, refined or hydrogenated (trans fat).  Saturated, monounsaturated or polyunsaturated fats can all be damaged.  Damaged fats have been altered from their true form in nature and transformed into fats that the body cannot effectively utilize.  Saturated fats are least likely to be damaged because of their stable nature, unless they have been hydrogenated.  Monounsaturated and polyunsaturated fats are the ones we really have to watch out for.  These fats can easily go rancid (oxidize) when exposed to light or heat because they are more unstable.  Oils sold in clear bottles are often already rancid.  Any oil that is refined is rancid and thus damaged.  Hydrogenated oils, or trans fats, are rancid and refined, definitely damaged fats.

The Process of Refining Oils

Ever wonder how we get corn oil?  It is difficult to imagine squeezing oil out of a corn kernel, but not so hard to imagine squeezing oil out of an olive. To make corn oil, corn kernels are heated and squeezed under high pressure, treated with chemical solvents to get every drop of oil out, then refined further through the processes of degumming, neutralizing, bleaching and deodorizing.  What’s left after the vitamins, minerals and antioxidants have been destroyed?  A rancid oil with damaging free radicals and harmful preservatives, devoid of any nutritional value.  Definitely not a health food.

In contrast, organic extra virgin olive oil that is expeller or cold pressed is an unrefined oil.  The olives are cleaned and then sent through a mechanical press without exposure to light or heat.  The oil is not processed any further and is packaged in opaque bottles.  The valuable nutrients in the oil remain intact and are not destroyed through processing.  Organic expeller pressed olive oil should be green in color and smell fruity.

The Process of Hydrogenation

The process of hydrogenation creates damaged fats.  For example, to make margarine, an already rancid vegetable oil is heated under pressure in the presence of hydrogen gas and a catalyst, usually nickel oxide.  This saturates the double bonds in the vegetable oil with hydrogen.  Because this process causes the oil to smell quite foul, it has to be deodorized.  The oil is gray at this point and has to be bleached.  Dyes and flavorings are then added so that the margarine looks and tastes like butter.

Hydrogenated fats are solid at room temperature, have a long shelf life and are cheap.  There is no nutritional value left in the oil.  In fact, hydrogenated fats are harmful and have been linked to all sorts of health issues.  They negatively affect your metabolism, increase cholesterol levels by causing damage to blood vessels and disrupt your immune system.  Hydrogenated fats have been associated with many diseases, including cancer, diabetes and obesity.

Foods with Damaged Fats

Many boxed and packaged foods contain damaged fats.  Manufacturers strive for long shelf lives with far off expiration dates so that foods stay “fresh” during transportation and storage.  We used to see a lot of hydrogenated oils in boxed and packaged foods; however, with the recently unveiled health concerns of trans fats, food manufacturers are trying to steer clear of trans fats and find alternatives. Buyers beware though; many foods labeled as “trans fat free” actually contain trans fats. You must learn to read labels carefully and look at the fine print.  Anytime you see “hydrogenated” or “partially hydrogenated” on a food ingredient label, that means the food contains trans fat. Manufacturers can legally get away with labeling a food “trans fat free” if it contains less than 0.5 grams trans fat per serving.

Preserved, refined oils are replacing trans fats in many boxed and packaged foods.  These refined fats are damaged fats and must be avoided as well. Again, we must learn to read ingredient labels.  If an oil in the ingredient label does not say unrefined, expeller or cold pressed you should assume it is a refined oil.  If an oil lists a preservative with it, that is a sure sign it is refined.

Foods that may contain damaged fats:

These foods should be avoided or carefully evaluated

• refined vegetable oils
• shortening
• margarine
• non-dairy creamer
• crackers
• boxed cereals
• breads
• tortillas
• muffins
• pancakes
• pastries
• cookies
• cake
• pie crust
• candy
• ice cream
• peanut butter
• chips

Healthy Fats

Chose stable saturated fats and unrefined vegetable oils for eating and cooking.  Saturated fats such as butter and unrefined coconut oil are great choices.  Butter is made simply by churning heavy cream.  You can make your own butter by shaking heavy cream at room temperature in a jar until it becomes solid.  Salt is often added to butter as a preservative to increase its shelf life; purchase unsalted organic butter for the most nutritious and freshest option.

Coconut oil is a very protective fat from the tropics where there is a high prevalence of bacteria and fungus in the food supply.  Coconut oil kept at room temperature for two years shows no signs of rancidity!  It is one of the most stable oils, as it is slow to oxidize, a healthy alternative to the many unstable vegetable oils.

Even unrefined (versus refined) vegetable oils should be used sparingly.  Purchase vegetable oils in opaque bottles that are labeled as unrefined, expeller or cold pressed and store them away from light and heat.  Many people like to keep their oils next to the stove because they are handy to cook with; however, heat damages the oil, causing rancidity.  Store oils in a cool, dark place.  Use unrefined olive oil as your main liquid oil in place of other vegetable oils.  Olive oil is  monounsaturated, a more stable fat than polyunsaturated oils, and it is easy to find in an unrefined state.

Cooking with Fats

Only certain fats should be used to cook with.  When sautéing under high heat, use butter, coconut oil, palm oil or tallow.  These fats are classified as saturated fats and can withstand higher heats without becoming rancid.  Olive oil should only be used for sautéing with light heat.  When baking, I recommend using butter in place of vegetable oils.

Healthy fats to include as part of your daily diet:

• organic butter
• organic ghee (clarified butter)
• organic cream
• coconut oil, unrefined expeller pressed
• coconut milk
• palm oil, unrefined expeller pressed
• olive oil, unrefined expeller pressed
• avocados
• olives
• nuts and seeds
• nut butters
• flax oil
• wheat germ oil
• salmon oil
• organic chicken fat
• organic lard
• organic tallow
• *unrefined expeller pressed vegetable oils such as avocado, canola, peanut, safflower, sesame, or sunflower

*use sparingly

Damaged fats are plentiful in our food supply and destructive to our health.  Knowing which fats to chose and which ones to avoid is key.  If you follow the recommendations above, you will be on the right track to making healthful choices about fats.